Pressure relief attachment



June 19, 1934. W. P. HUFFMAN ET AL PRESSURE RELIEF ATTACHMENT Filed Jan.. 29. 1952 ATTORNEYS gig; f

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Patented June 19, 1934 UNITED STATES ,Law-0 PRESSURE RELIEF ATTACHMENT William P. Huffman and Frederick F. Rike, Dayton, Ohio, assignors to Buckeye Iron 'and Brass Works, Dayton, Ohio, a corporation of Ohio Application January 29, 1932, serial No. 589,686

16 Claims.

This invention relates to an attachment adapted to be used in connection with the delivery pipe of a gasoline dispensing apparatus and to act as an expansion chamber for relieving the pressure in the delivery pipe and its connections due to the expansion of the gasoline therein, and the formation of gases or vapors arising from Vaporization of the liquid, caused by the heat of the sun acting in warm weather on the pipe and its connections; or where such expansion is due to any condition which causes an increase in such pressure. It is particularly the object of this invention to provide a reservoir of an expansible character so as to yield more and more as the excess of pressure may increase, and to locate such attachment between or adjacent to the delivery pipe and the meter. f

It is a further object of this invention to provide a reservoir in which the interior chamber is made expansible by a diaphragm or partition capable of moving or yielding within the reservoir casing, and held by spring means so as t0 yield as the pressure increases; or the expanded liquid and/ or gases or vapors increase in volume.

Referring to the drawing: Y

Figure 1 is a vertical section through the up-A per part of the casing showing one part of the delivery pipe and hose, with applicants attach` ment properly connected to the delivery pipe.

Figure 2 is a vertical section through the attachment.

Figure 3 is a section on the line 3 3 of Figure 2.

Figure 4 is a section on the line 4 4 of Figure 2.

. Under normal operation of any gasoline dispensing apparatus the pressure in the delivery line and the hose, when the valve is open, is ten pounds or less. When the valve is closed this pressure may be increased to twenty pounds, due to the recirculation of the gasoline through the by-pass in connection with the pump. During increased temperature the normal pressure of the gas in the pipe and hose may be increased to such an extent that an explosion would take place and result in bursting either the hose or pipe, or damaging the valve.

Even though these parts are not broken or ruptured, a leaking oi' gasoline vapors may occur, thereby causing a loss in addition to creating unpleasant odors about the delivery apparatus, and also increasing the danger of re and explosion. This increase of pressure, due to summer heat, may become as much as forty pounds per square inch or more, and unless the parts are very secure explosion may result. It is fon the purpose of relieving this pressure that the present attach.. ment is provided, and is attached to the delivery pipe between the meter and the hose.

In Figure 1 a part of the upper end of the cas-V ing 1 is shown, on one side of which is a dial. 2 to indicate the amount of gasoline delivered or dispensed. The gasoline is being` dispensed thro-ugh a supply pipe 3, which delivers the fluid or gasoline to a meter chamber 4, from which a discharge pipe 5 conducts the gasoline to a hose 6. On the free end of this hose is a nozzle and valve- 7. The nozzle is for delivering the gasoline into a tank or spout, while the valve controlsthe opening through the nozzle. As the gasoline passes from the discharge pipe into the hose it passes through a sight gauge 8, usually found in connection with gasoline dispensing'apparatus.

The present attachment consists of a casing or cylinder constituting an expansion chamber composed of two parts, a lower shell part 9 and an upper dome-shaped part 10, threaded into the upper cylindrical part of the shell 9. Bel-I tween the dome andthe shell part iszagasket 11. This gasket cooperates with the threaded .connection, between the shell andthe dome, to form` a gas and liquid-tight seal. The part of the shellv below the dome is formed into a chamber12, forming part of an expansion chamber, which is more or less vertical in its disposition and has in its lower end a small inlet opening `13 by'which the gas or vapor passes into the chamber 12.1..

Around the chamber 12 and within the .Shelli is an annular trough 14, which has around it, and formingone of the walls thereof, an annular seat 15. Fitting within the casing or cylinder formed by the dome is a' plunger, pistonor para. tition 16. The purpose of this partition or pistony is to provide means for increasing the' expansion chamber by enlarging the space in theA lower part of the housing formed by the shell, partition and part of the dome so that space 'may 'be'prof-r vided for expansion in the liquid orLreceptionj ofi` vapors formed from the liquid.

Around the periphery of this plunger is Yan an'- nular shoulder 17, which has resting thereon one edge or an annular packing 18. `This packing may: be of leather, rubber Vor any suitable material, and is cup-shaped, as shown in Figure 2, with theA open part extending downwardly from the annu lar shoulder 1'7. shoulder by means of a ring 19 threaded' on piston or plunger above the packing.

There is also provided below the shoulder 17 an annular seat for a garter spring 20. This is ai,

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This packing is held on 'the' n 'KOI compression spring and tends to hold the packing 18 against the inside walls of the dome 10 as the plunger moves back and forth in the dome.

In the central part of the lower surface of the plunger is provided a seat for a packing 2l. This packing is held in place by means of a disc 22, which has on one side thereof a stem 23 threaded into the central part of the plunger, while on the other side there is a guide stem 24 suitably fitting in a hole in a spider 25. The spider serves to guide the stem and the disc 22 as they move vertically.

The disc 22 and the packing 21 are round. The disc is adapted to fit within the annular seat, while the packing is adapted to rest upon the annular seat 15 and form a tight sealing engagement therewith. When the packing 21 is upon the seat 15 the trough 14 is distinctly separated from the chamber 12 so it is possible for an unbalanced condition of pressure to exist between the chamber and the trough, if some means is not provided for 4relieving this unbalanced condition. This means will be later on described.

Extending downwardly from the top and within the dome is a boss 26, which has a hole 27 therein. On the upper side of the plunger is a boss 28 into which one end of a guide stem 29 is threaded. The other end of this guide stem ts into the rhole 27 and is guided therein by means of the boss 26. This boss 26 and the guide stem 29 tend to aid in the proper positioningof the plunger, and maintaining this plunger in its proper position with relation to the sides of the dome. y

Between the upper end of the dome andthe plunger is a spring 29a, which serves to maintain the plunger in its lower position, with the packing 18 seated uponv the annular seat l5. This spring, in addition to maintaining the plunger orV piston in its lower seated position, also will serve to limit the upward movement of the plunger vbecause when the coils of the spring contact the plunger cannot be moved farther upwardly.

. Other means is also provided for limiting the upward movement of the plunger. This means consists of a stop flange 30, extending around the inside'of the dome, as shown in Figure' 2. This flange may be diiferently positioned so as to vary the upward limit of the plunger. The size of the spring may also be varied. The'spring may be made weaker and also the coils may normally be spaced farther apart than shown in Figure 2, thereby making it possible to increase the range of movement of the plunger or piston; also thereby increasing the amount of space to take care of any expansion that may take place in the liquid, or the amount of vapor that may be received from the liquid.

In the shell adjacent one side of the chamber 12 is a pocket 3l, circular in shape and vertically located. Extending from the trough 14 downwardly is a passageway 32, which has its'lower end connected by means of an inlet 33 to the pocket 31, thereby providing a direct communication between the trough and the chamber 12. This communication is controlled by means of a valve located within the pocket 31.

Located at the lower end of this pocket 31 is a packing or washer 34, which has an opening in the center thereof in line with the inlet 33. This packing is held in position by means of an inverted thimble member 35, which has in its upper end one or more outlets 36. This thimble is circular Von its interior, and has located therein a hexagonal plug member 37,`which serves as a valve to close the inlet 33. This valve is made of metal and is sufficiently heavy to maintain itself seated on the washer 34 until some considerable pressure accumulates in the passageway 32. After the accumulated pressure has been released by raising the valve the pressure condition between the trough and the chamber is substantially identical. In order to relieve pressure in the upper end'of the dome, or to release the accumulation of vapor therein, a discharge cock 33 is provided.

Whenever the gasoline in the various pipes and the hose becomes heated it expands and vaporizes. This expansion is taken care of by means of the attachment herein described. When an increase of pressure is brought about either the liquid or vapor will pass through the inlet 13 in the chamber l2. When the pressure becomes sufficient the plunger is moved upwardly against the action ofV the spring 29a, thereby providing a space to take care of the increased volume of liquid or the production of vapor. The greater the pressure the higher the plunger will be forced against the action` of; the spring.

While a plunger or piston has been shown, other movable diaphragm or partition member may be used, the object being to provide a space that will, under pressure, be increased for taking care of the formation of the vapor or the expansion 0f the liquid.. In the present form one means is illustrated for providing an expansion chamber for taking care of the creating of vapors from the expansion of the liquids. Y v

Thus, in effect, there is provided an expansion chamber with means for permitting the flow therein ,of Vvarying volumes of gases or vapors caused by the evaporation of the contained fluid; and for the accommodation of any expansion in such liquid due to increases in temperature. The prime feature lies in this expansible chamber for this purpose.

`Thus also it will be understood thatour invention comprises a piston or partition of differential diameters, larger and smaller, with a seat for the smaller area, with a Spring to yieldingly permit the partition or piston to be held to such seat and to yield with varying pressures of the gases or vapors and the vexpanding liquid, with means for admitting the flow therein first tothe smaller area of the rst partition or piston.

When the pressure is sufficient the smallerarea is lifted from its seat and the expansion pressures then reach the larger area, after which both the larger and smaller areas are acted upon by such pressure, while with a suicient lowering ofthe pressure, as by reduction of the temperature or the opening of the nozzle valve, the spring will react and reseat the smaller area of the partition or piston. These operations repeat themselves from time to time, but always with the elect of yielding to the pressures and thereby enlarging the interior of the expansion chamber.

When the valve in the hose nozzle is closed, if the motor is allowed to operate the pump for more or less a period, as by oversight of the attendant, then the gasoline in the delivery pipe will by-pass, but the liquid will not be diverted into entering the expansion chamber because during such period the pressure is not sufficient to cause the' piston or partition to lift in the chamber, for the reason that at such time only the smaller area of the piston or partition is exposed to the pressure. The pressure is not then great enough, when confined as it then is, to acting on the smaller area, to lift and unseat the piston or partition. Ac-

cordingly, none of the gasoline will be diverted into the chamber during the period the motor is running and by-passing the gasoline, and the valve of the nozzle is closed. This acts in turn to preserve the full quantity of gasoline in the delivery pipe and hose by preventing it, or any part of it, from entering the expansion chamber. This period of prevention continues until the pressure is built up a suflicient degree to lift the piston or partition while acting only on the smaller area. After the pressure has suiciently accumulated to unseat the piston or partition, though acting only on the smaller area, then the pressure will have access to the larger area also. But that will not take place during any period. of the by-passing of the liquid.

We desire to comprehend within our invention such modifications as may be embraced within our claims and the scope of our invention.

Having thus fully described our invention, what we claim as new and desire to secure by Letters Patent, is:

1. In a pressure relief attachment, an expansion cylinder having an inlet, a trough around the inlet and a wall between the trough and the inlet, said wall forming a seat, a plunger forming a piston in the cylinder adjacent the inlet, and means tending to hold the plunger on the seat but adapted to yield to pressure, said trough being connected to the inlet by a passageway.

2. In a pressure relief attachment, an expansion casing having an inlet and an annular valve seat around the inlet, a partition in said casing adapted to rest on the seat and be removed therefrom by pressure through the inlet, and means to equalize the pressure on one side of the partition and on opposite sides of the seat when it is on the seat.

3. In a pressure relief attachment, a casing having therein a yielding piston member dividing the casing into two parts and an inlet to admit a fluid to said casing on one side of said member, a seat in the casing around the inlet, and forming a wall of a trough around the inlet, said trough l' being con ected to the inlet by a valve-controlled passageway, sealing means on said member adapted to engage the seat, and means tending to hold the sealing means on the seat so that when the fluid first enters the casing it Will press against the sealing means and after the sealing able plunger in said dome adapted to rest on the seat, and means tending to hold the plunger on the seat, said plunger when on the seat forming a pressure chamber to give the plunger its initial movement in the formation of a large expansion chamber.

5. In a pressure relief attachment, a casing consisting of a shell and a dome removably attached to the shell, said shell having therein a chamber having an inlet at one end and an annular seat around the other end, and a passageway from adjacent the seat to the chamber, a plunger forming a piston in said dome adapted to rest upon the seat, means in the chamber to guide the plunger, and means tending to hold ythe plunger on the seat.

6. In a pressure relief attachment, a casing consisting of a shell and a dome attached to the shell, said shell having therein a chamber having an inlet at one end and at the other end an annular seat around the chamber and a trough around the seat, a reciprocating member in said dome adapted to rest upon the seat, means tending to hold said member upon the seat, and means to equalize in one direction the pressure in the chamber and that in the trough when the reciprocating member is on the seat. Y

'7. In a pressure relief attachment, a casing consisting of a shell and a dome, said shell having an extension with a chamber therein having an inlet, an annular seat around one end of the chamber and forming with the adjacent shell structure a trough, means in the casing adapted to rest upon the seat and cooperating with the casing to form with the shell chamber an expansion chamber, a pressure relief between the trough and the chamber, and a guide in the shell chamber to guide the rst-named means.

8. In a pressure relief attachment, a casing consisting of a shell and a dome, said shell having an extension forming a chamber having an inlet, an annular seat around one end of the chamber and forming with the adjacent shell structure a trough, means in the casing adapted to rest upon the seat and cooperating with the casing to form with the shell chamber an expansion chamber, a pressure relief between the trough and the chamber, and a guide in the shell chamber to guide the rst-named means, said guide consisting of a stern and a spider in the shell.

9. In a pressure relief attachment, a casing consisting of a shell and a dome, said shell having an extension forming a chamber having an inlet, an annular seat around one end of the chamber and forming with the adjacent shell structure a trough, means in the casing adapted to rest upon the seat and cooperating with the casing to form with the shell chamber an expansion chamber, a pressure relief between the trough and the chamber, and a guide in the shell chamber to guide the iirst-named means, said guide consisting of a stem threaded into said means and a spider in the shell 10. In a pressure relief attachment, a casing consisting of a shell and a dome, said shell having an extension forming a chamber having an inlet, an annular seat around one end of the chamber, a plunger forming a piston in said dome adapted to rest upon the seat and cooperating with the casing to form with the shell chamber an expansion chamber, a gasket on the plunger to engage the seat, a guide stem threaded into the plunger through the gasket, and means to guide the stem.

ll. In a pressure relief attachment, a casing consisting of a shell and a dome, said shell having an extension forming an attaching means forming a chamber having an inlet, an annular seat around the chamber and forming with the adjacent parts of the shell a trough, a plunger forming a piston in the dome adapted to rest upon the seat and be moved ofi the seat due to pressure in the chamber to form an expansion chamber, and a valve-controlled by-pass from the trough to the chamber. l

12. In a pressure relief attachment, a casing having at one end a chamber, an inlet to the chamber and a seat around the chamber forming a trough, a reciprocating member in the casing cooperating With the casing to form in combination with the chamber an expansion chamber, and means to by-pass pressure from the trough to the mst-named chamber.

13. In a pressure relief attachment, a casing having at one end a chamber, an inlet to the chamber and a seat around the chamber forming a trough, a reciprocating member in the casing cooperating with the casing to form in combination with the chamber an expansion Chamber, and means to by-pass pressure from the trough to the first-named chamber, said means consisting of a passageway having a valve therein.

14. In a pressure relief attachment, a casing having at one end a chamber, an inlet to the chamber and a seat around the chamber forming a trough, a reciprocating member in the casing cooperating with the casing to form in come bination with the chamber an expansion chain1 ber, and means to by-pass pressure from the trough to the first-named chamber, said means consisting of a passageway terminating in a chamber, a thimble member having an outlet to the vfirst-named chamber, and a iioating valve in the thimble.

15. In a pressure relief attachment, a casing having a trough and an inlet at one end, said trough being connected to the inlet by a passageway, a plunger forming a piston in said casing, means in the casing tending to hold the plunger adjacent the inlet but adapted to yield to pressure on the plunger so that an eXpansible chamber is formed, a valve in said passageway, and a stop in the casing for the plunger 15. In a pressure relief attachment, a casing having an inlet in one end and a relief cock adjacent the other end, a plunger forming a piston in said casing, means in the casing tending to hold the plunger adjacent the inlet but adapted to yield to pressure on the plunger to form an eXpansible chamber, and a flange in the chamber to form a stop for the plunger.

WILLIAM P. HUFFMAN. FREDERICK F. RIKE.

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